It has been necessary for the headlamp for vehicles, particularly automobiles to have a distribution pattern such that the lane of travel is brightly illuminated without dazzling drivers of the automobiles running in the opposite lane. There has been proposed a so-called projector type headlamp as a headlamp having the distribution pattern satisfying such requirement mentioned above, a simple lens arrangement, and a compact size. For example, U.S. Pat. No. 4,511,955 discloses the headlamp of such type in which the reflecting surface of the reflector is formed in a revolutional ellipse and the luminosity distribution of a pattern is dependent on the formation of the reflector even though a particular distribution pattern can be obtained. Namely, it is possible to change the luminosity distribution of the distribution pattern in a constant range by changing the eccentricity of the ellipse, however it is the luminosity distribution inherent in an ellipse and it has a constant similarity. Therefore, the luminosity distribution of the distribution pattern is generally decided by the formation (a revolutional ellipse surface, a revolutional parabolic surface) of the reflector's surface, so that there is no sufficient freedom in design for obtaining a desired luminosity distribution. The object of the present invention is to present a novel headlamp of the projector type in which the above-mentioned drawbacks of the conventional headlamp of the projector type is eliminated.
The other object of the present invention is to present a headlamp in which the reflecting surface of the reflector is composed of a great many minute face elements connected with each other continuously and smoothly, the orientation of each face element is different from each other so as to obtain a desired luminosity distribution, and it is setable voluntarily to a distribution pattern having a desired luminosity distribution.
Still the other object of the present invention is to present a projector type headlamp in which the orientation of each face element is decided such that the maximum luminosity region in the distribution pattern is substantially not affected with any influence by a shade for providing a light-dark boundary.